Graying hair

Have you ever wanted to see how someone would look with gray hair? Now here's your chance. Follow along with this tutorial to transform the hair of any person to look gray. Start by opening an image of a woman.
Create selection of the hair using polygon lasso tool. Press Alt+Ctrl+D to feather the selection. Feather the selection by 2 pixels.
Press Ctrl+J to copy paste the selection in a new layer. Press Ctrl+L to open level settings. Apply settings as shown.

Press Ctrl+Shift+U to desaturate the layer.
Select eraser tool with soft brush settings. Apply the eraser on the edges of the hair.
Select dodge tool with the brush settings shown on the options bar at top.

Select the image layer and apply the dodge tool on the dark hair areas.